CTLA4 and melanoma: The use of immune checkpoint inhibition (ICI), monoclonal antibodies blocking programmed death receptor-1 (PD-1), programmed cell death-ligand 1 (PD-L1), or cytotoxic T-lymphocyte associated protein 4 (CTLA-4), has lately become the standard of care for several malignancies such as melanoma, non-small cell lung cancer, and renal cell carcinoma [2, 3].